This does happen yes.
I mean im not saying it doesn't but given there is a single result (this thread) in google on the following search term:
hacked.txt "secure your server idiot"
Im guessing it isn't some white knight and neither is it an automated script.
To be honest it also sounds like the op has just wacked new software on in an attempt to secure but it might even already be too late, if it was me and I was looking to mess with the op id be deploying keylogging software etc and I can guarantee little old avast wouldn't have a clue. Then when it settles in a few weeks / months im back again.